M_Boats: Mast gates

After getting the brochure about the Mastgate product line of products I was surprised to find that the mastgate itself is held in place with just shock cord. Has anybody installed one of these and found it to withstand the various strains and pressures placed upon it such that it didn't dent or pop out of place or malfunction in any other fashion? Would like to hear about your experiences with this product. Thanks, Tom B M17, #258